Lamp assembly for edge-lighted panel



y 1965 E. MADANSKY 3,183,344

LAMP ASSEMBLY FOR EDGE-LIGHTED PANEL Filed June 11, 1962 United States Patent 3,183,344 LAMP ASSEMBLY FOR EDGE-LIGHTED PANEL Leslie E. Madansiry, Burbank, Califi, assignor to California Plasteck, Inc., Reseda, Calif, a corporation of California Filed June 11, 1962, Ser. No. 201,414- 8 Claims. (1. 240-816) This invention relates to a lamp housing for mounting a lamp bulb in an edge-lighted panel of the type commonly used in the cockpit of an aircraft. Such a panel is of laminar construction having a thick main transparent layer covered on both faces by thin translucent layers which, in turn, are covered by outer opaque layers. On the front face of the panel the opaque layer has indicia cutouts that are illuminated by interior light transmitted from the main transparent layer through the adjacent translucent layer.

It is common practice to use lamp bulbs of greater dimension than the thickness of the panel and to mount the lamp bulbs in lamp housings that extend into wells or bores in the panel from the rear side of the panel. For energization of the lamp bulbs two circuit conductors are incorporated into the laminar construction of the panel adjacent each of the wells in which the lamp housings are mounted. The two conductors are typically printed circuit conductors lying in the same plane on opposite sides of the lamp well, the conductors being embedded under the translucent layer on the back face of the panel.

The problem to which the present invention is directed is to provide a lamp housing of simple reliable construction for convenient installation in a well in a panel in electrical communication with the two adjacent printed circuit conductors on the panel. The lamp housing should be firmly mounted in the well and convenient access to the interior of the lamp housing should be provided for replacement of lamp bulbs. Preferably each well in the back face of the panel is relatively shallow to fall short of the front face of the panel to avoid reducing the area of the front face that is available for indicia.

In the practice of the present invention, the panel is formed with a well in the form of a blind bore in the rear face of the panel and the rim of the blind bore is formed with an annular recess. The lamp housing includes a cylindrical member or sleeve which is permanently bonded in the blind bore of the panel and which has a radial flange electrically connected to one side of the lamp bulb. This radial flange seats in the annular rim recess in contact with one of the two printed circuit conductors of the panel but the radial flange does not extend all the way around the sleeve. Thus the radial flange has a circumferential gap and the second printed circuit conductor of the panel extends into this gap.

The lamp housing further includes a conductive ring which surrounds the housing sleeve above the radial flange and which is insulated from the radial flange. A bushing or nut of non-conducting material engages the conductive ring and also screw-threadedly engages the housing sleeve to press the conductive ring against the second printed circuit conductor in the region of the gap in the radial flange. A removable conductive cap screw-threadedly engages the conductive ring and electrically connects the conductive ring to the second side of the lamp bulb. Thus the invention provides for both of the printed circuit conductors of the panel to extend into the rim recesses, one of the two conductors being contacted by the radial flange of the lamp housing, the other of the two panel conductors extending into the circumferential gap of the radial flange and being engaged by the outer conductive ring of the lamp housing.

Patented May El, 1965 The features and advantages of the invention may be understood from the following detailed description and the accompanying drawing.

In the drawing, which is to be regarded as merely illustrative:

FIG. 1 is a view largely in longitudinal section and partly in side elevation illustrating the presently preferred embodiment of the invention;

FIG. 2 is a transverse section taken as indicated by the line 2-2; of FIG. 1;

FIG. 3 is a radial section of the installed lamp housing and adjacent structure of the panel, the section being taken along the line 3-3 of FIG. 2;

FIG. 4 is a similar radial section taken along the line 4-4 of FIG. 2;

FIG. 5 is a perspective view of a sleeve member of the lamp housing; and

FIG. 6 is a fragmentary sectional view illustrating a modified form of the invention.

FIG. 1 shows a lamp housing of the present invention generally designated L mounted in an edge-lighted panel that is generally designated P. The edge-lighted panel P is of laminar construction with a relatively thick main layer 19 of transparent plastic, a thin transparent layer of plastic 12 covering the front face of the main layer, and a second translucent layer 14 covering the back face of the main layer. The two translucent layers 12 and 14 are covered in turn by thin outer opaque layers 15 and 16, the opaque layer 15 on the front face of the panel being formed with cutouts to provide indicia that are illuminated from the interior of the panel through the front translucent layer 12.

A Well 18 extends into the panel from the back face thereof to receive the lamp housing L and in this particular practice of the invention the well is in the form of a blind circular bore. The blind bore leaves a thin web 20 of the material of the panel between the end of the bore and the front face of the panel.

A first lamp circuit conductor 22 on one side of the lamp circuit is on one side of the well 13 and a second conductor 24 on the second side of the lamp circuit is on the other side of the Well. In a well-known manner, these two circuit conductors are printed circuit conductors embedded in the panel under the translucent layer 14 on the back face of the panel. For the purpose of the present invention the panel is counter-bored to form the well 18 with an annular rim recess 25. The cutting away of the material of the panel to form the annular rim recess 25 removes corresponding portions of the rearward opaque layer 16, the rearward translucent layer 14 and the two embedded circuit conductors 22 and 24.

The purpose of the lamp housing L is to mount a lamp bulb 26 in the well 18 in the plane of the main transparent layer it of the panel. In this instance the lamp bulb has an extensive circumferential contact 28 in the form of a ferrule and has an end contact 30. The ferrule or circumferential contact 28 forms an outer circumferential shoulder 32.

The principal parts of the lamp housing L, include: an externally threaded sleeve 34 having a conductive radial flange 35 that seats in the annular rim recess 25, the radial flange being in the region of the first conductor 22 and extending only part Way around the circumference of the sleeve to provide a gap in the region of the second conductor 24; a conductive ring 36 having an inner circumferential shoulder 38; a bushing iii of non-conducting material such as a suitable plastic in abutting engagement with the inner circumferential shoulder 38 of the conductive ring 36 and in screw-threaded engagement with the sleeve 34 to press the conductive ring against the panel; a removable cap 42 in screw-threaded engagement assistwith the conductive ring 35 to close the outer end of the housing; and a spiral spring id in compression between the inner end of the cap 42 and the end contact of the lamp. It is apparent that the conductive ring is in electrical communication with the end contact 39 of the lamp bulb through the metal cap 42. and the spiral spring 44.

The sleeve 34 has a light-transmitting plastic portion 45 to permit the lamp bulb to illuminate the interior of the main transparent layer 10 of the panel P. This lighttransmitting portion 45 of the sleeve, which may be colored for illumination of a panel with colored light, is adhesively bonded in the well 18 and has an end wall 46 which lies at the inner end of the we 1 18. The sleeve 34 further has a cylindrical metal portion 48 which provides the above-mentioned conductive radial flange and which is further formed with the external screw thread for engagement by the non-conductive bushing 49. The plastic portion 45 of the sleeve 34 is molded to the cylindrical metal portion 48 to form a unitary sleeve, the cylindrical metal portion being formed with a circumferential bead 52 for interlocking of the two portions.

As indicated in FIG. 1, the ferrule or circumferential contact 28 of the lamp bulb 26 seats on the cylindrical metal portion 48 of the sleeve 34 with the bulb of the lamp extending into the interior of the plastic portion 45 of the sleeve. Thus the radial conductive flange 35 of the sleeve is in electrical communication with the circumferential contact 28 of the lamp bulb. V

In the construction shown, the non-conductive bushing extends beyond the end of the sleeve 34 and is reduced in diameter to yieldingly embrace the ferrule or circumferential contact 28 of the lamp bulb. If desired, a cylindrical non-conductive member as may be added and bonded to the bushing 41) to serve in effect as an upward extension of the bushing for more extensive engagement with the circumferential contact of the lamp bulb. The preferred procedure for assembling the lamp housing to the panel is as follows. The first conductor 22 of the panel is extended into the annular recess 2'5 and radially across the bottom of the recess for contact with the conductive radial flange 35 of the housing. For this purpose printed circuit material is painted onto the panel in the manner shown in FIG. 4 and cured to form an angular extension 54 of the first panel conductor 22.

The second step is to insert to sleeve 34 alone of the housing into the well 18 and to anchor the sleeve in the well with the conductive flange 35 snugly overlying the angular extension 54 of the first panel conductor 22. For this purpose the periphery of the plastic portion of the sleeve 34 may be coated with a suitable light-transmitting adhesive or cement for bonding the sleeve to the inner circumferential Wall of the panel well 18. a

The next step is to fill the remaining unoccupied per tion of the annular rim recess 25 with a body of epoxy V 55, the epoxy being preferably applied to at least approximately the level of the outer surface of the housing flange 35. Additional epoxy indicated at 56 in FIG. 4 is extended over the outer surface of the conductive flange 35.

After the epoxy body and the additional epoxy as are cured, the second panel conductor 24 is extended over the epoxy body 55 in the region of the gap of the radial conductive flange 35. For this purpose printed circuit material indicated at 58 is painted onto the epoxy body 55 and cured to serve as an extension of the second panel conductor 25, the added printed circuit material terminating short of the cylindrical metal portion 58 of the sleeve 34. The applied printed circuit material '58 is thick enough to extend outward at least to the plane of the outer surface of the additional epoxy 56. V

The conductive ring 36 is then placed in its assembled position and the non-conductive bushing 40 is screwed 'onto the sleeve 34 into abutment with the. inner circumferential shoulder 38 of the conductive ring to press the conductive ring into firm contact with the printed circuit extension 58 of the second panelconductor 24. The.

provision of the additional epoxy 56 diametrically op- .41. posite from the printed circuit material 58 provides a second equalizing bearing point for the conductive sleeve 34.

The final step is to insert the lamp bulb into the non conducting bushing 40 to seat on the metal end of the sleeve 45. The cap 42 is then screwed into the conductive ring as to complete the installation.

If desired, the epoxy coating 56 on the outer surface of the radial flange 35 may be applied to the flange and cured in advance of the installation of the lamp housing in the panel.

FIG. 6 indicates how the invention may be modified to eliminate the necessity for providing the epoxy body 55 and the additional epoxy 56 at the time of installation. This modified form of the invention is similar to the first described embodiment except that the sleeve 34a not only has the usual metal flange 35:: but also has a non-conductive flange 55a of the configuration of the previously described epoxy body 55 and the sleeve further has a plastic covering 56a for the metal flange 35a, the plastic portion 45a of the sleeve 34a, being formed when the plastic portion 45a is molded to the metal portion 48a of the sleeve. 7

It is apparent that the sleeve 34:: of the modified form may be regarded as having a single circumferential radial flange, one portion of the circumferential flange on one side of the sleeve being made of metal and another portion of the flange on the opposite side of the sleeve being made of plastic.

My description in specific detail of the selected practices of the invention will suggest various changes, substitutions and other departures from my disclosure within the spirit and scope of the appended claims.

I claim: 1. In an edge-lighted panel assembly, the combination of:

a panel having a main relatively thick light-transmitting layer and having a well extending into the main layer from one face of the panel withan annular recess in said one face around the rim ofthe well;

a lamp circuit incorporated in the panel including a first conductor and a second conductor adjacent said rim recess, a portion of said first conductor extending into the annular rim recess;

a lamp bulb with a circumferential contact and an end contact;

a lamp housing holding said lamp bulb in said well;

7 a sleeve included in said housing and fixedly attached to the panel to seat said circumferential contact of the lamp bulb, said sleeve being externally threaded and having an outward conductive flange seated in said annular recess in contact with said portion of the first conductor, said outward flange extending only part way around the circumference of the annular recess and having a circumferential gap in the annular recess in the region of the second conductor of the panel, a portion of said second conductor extending into said gap of the flange;

a layer of non-conducting material covering the outer surface of said flange;

a conductive ring included in said housing and surrounding said sleeve at radial spacing from the sleeve, said ring having an inner shoulder;

a conductivecap included in said housing in screwthreaded engagement with said conductive ring to close the outer. end of the housing and to connect the conductive ring with the end contact of the lamp bulb; and V an internally threaded non-conductive bushing in engagement with said shoulder of the conductive ring and in screw-threaded engagement with said sleeve to press the conductive ring against said portion of the second conductor.

2. A combination as set forth in claim 1 in which a portion of said non-conductive layer that covers the outer surface of said flange extends into said recess at said gap; and

in which said portion of the second conductor overlies said portion of the non-conductive layer.

3. A lamp housing for mounting a lamp bulb in an edge-lighted panel that has a Well on its rear face with an annular recess around the rim of the Well and has two conductors of a lamp circuit adjacent the rim of the well, said lamp bulb having a circumferential contact and an end contact, said lamp housing comprising:

a light-transmitting housing body adapted for bonding to the panel with the body extending into said well;

a conductive sleeve united with said body to seat said circumferential contact of the lamp bulb and having a radially outward flange in the form of a segment of a disk positioned and dimensioned to seat in said annular rim recess with the inner surface of the flange in contact with one of said two conductors, said flange being axially spaced substantially from the inner end of said body and extending only part of the way around the periphery of the sleeve with a circumferential gap in the flange for positioning in the region of the second conductor of the panel;

a layer of non-conductive material on the outer face of said flange; a conductive ring surrounding said sleeve at radial spacing from the sleeve, said ring having an inner shoulder;

a conductive cap in screw-threaded engagement with said conductive ring, said cap closing the outer end of the housing and electrically connecting the conductive ring with the end contact of the lamp bulb; and

a non-conductive bushing in engagement with said inner shoulder of the conductive ring and in screw-threaded engagement with said conductive sleeve to press the conductive ring against said layer of non-conductive material and against the other of the two conductors of the panel.

4. A lamp housing for mounting a lamp bulb in an edge-lighted panel that has a well on its rear face with an annular recess around the rim of the well and has two conductors of a lamp circuit adjacent the rim of the well, said lamp bulb having a circumferential contact and an end contact, said lamp housing comprising:

a conductive sleeve to surround said lamp bulb and seat said circumferential contact of the lamp bulb;

a sleeve of light-transmitting material united with said conductive sleeve coaxially thereof and adapted to be bonded to said Well for attaching the conductive sleeve to the panel, said conductive sleeve having a radially outward flange in the form of a segment of a disk positioned and dimensioned to seat in said annular rim recess with its inner surface in contact with one of said two conductors, said flange being axially spaced substantially from the inner end of said body and extending only part of the way around the periphery of the sleeve with a circumferential gap in the flange for positioning in the region of the second conductor of the panel;

a layer of non-conductive material on the outer face of said flange; a conductive ring surrounding said sleeve and having an inner shoulder; and

a non-conductive bushing in engagement with said inner shoulder of the conductive ring and in screwthreaded engagement with said conductive sleeve to press the conductive ring against said layer of nonconductive material and against the other of the two conductors of the panel.

5. In a lamp housing for mounting a lamp bulb in an edge-lighted panel that has a Well on its rear face With an annular recess around the rim of the well and has two conductors of a lamp circuit adjacent the rim of the Well, said lamp bulb having a circumferential contact and an end contact, the combination of;

a sleeve for mounting in said well, said sleeve having a radial flange in the form of a segment of a disk positioned and dimensioned to be electrically connected with one side of the lamp bulb, said flange being axially spaced substantially from the inner end of said body and being positioned to seat in said annular rim recess in contact with one of said two conductors of the panel, said flange extending only part of the way around the periphery of the sleeve with a circumferential gap in the flange for positioning in the region of the second conductor of the panel;

a conductive ring electrically connected with the other side of the lamp bulb, said conductive ring surrounding said sleeve and being insulated from said flange, said conductive ring having an inner shoulder; and

a non-conductive bushing surrounding said sleeve in screw-threaded engagement therewith, said bushing engaging said inner shoulder of the conductive ring to press the conductive ring against the other of said two conductors of the panel in the region of said gap in the flange.

6. A lamp housing for mounting a lamp bulb in an edge-lighted panel that has a well with an annular recess around the Well and has two conductors of a lamp circuit adjacent the well, said lamp housing including:

a body surrounding said lamp bulb for connection to the panel with the body extending into said well, said body being made in part of metal and in part of plastic, said body having a circumferential radial flange dimensioned to fit into said annular rim recess, a first portion of said flange on one side of the body being made of metal for electrical communication with one of said panel conductors and being in electrical communication with one side of the lamp bulb, a second portion of the flange on the other side of the body being made of plastic to support an extension of the other panel conductor; and

conductive means spaced radially outward of said body in electrical communication with the second side of the lamp bulb, said conductive means being adjustably connected to the body for adjustment towards said plastic portion of the flange for electrical communication with said other panel conductor.

7. A lamp housing as set forth in claim 6 in which said first metal portion of the radial flange of the body is substantially thinner than the second plastic portion for contact with a portion of said one of the panel conductors in a plane common with the second plastic portion of the radial flange.

8. A lamp housing as set forth in claim 7 in which the outer surfaces of said first and second portions of the body flange are substantially coplanar.

References Cited by the Examiner UNITED STATES PATENTS NORTON ANSHER, Primary Examiner. 

1. IN AN EDGE-LIGHTED PANEL ASSEMBLY, THE COMBINATION OF: A PANEL HAVING A MAIN RELATIVELY THICK LIGHT-TRANSMITTING FROM ONE FACE OF THE PANEL WITH AN ANNULAR RECESS IN SAID ONE FACE AROUND THE RIM OF THE WELL; A LAMP CIRCUIT INCORPORATED IN THE PANEL INCLUDING A FIRST CONDUCTOR AND A SECOND CONDUCTOR ADJACENT SAID RIM RECESS, A PORTION OF SAID FIRST CONDUCTOR EXTENDING INTO THE ANNULAR RIM RECESS; A LAMP BULB WITH A CIRCUMFERENTIAL CONTACT AND AN END CONTACT; A LAMP HOUSING HOLDING SAID LAMP BULB IN SAID WELL; 